Linkwork for reciprocating engines and the like



June 24, 1930. E. 'M. BYTHWAY 1,768,436

LINK WORK FOR RECJ IPROCATING ENGINES AND THE LIKE Filed'Nov. 14, 1927 1 5 Sheets-Sheet l //VVEN76F 5 M. BYTHWAK June 24, 1930. E. M. BYTHWAY LINK WORK FOR RECIPROCATING ENGINES AND THE LIKE Filed Nov. 14', 1927 5 Sheets-Sheet 15 //YVE -E. 1 1. BYTHWA)" 111319 4; 1930- I E. M; BQYTHWAY 1,768,436

LINK WORK FOR RECIPROCATING ENGINES AND THEILIKE Filed Nov/14, 1927 5 Sheets-Sheet 3 June 24, 1930. E. M. BYTHWAY 1,753,436

LINK WORK FOR RECIPROCATING ENGINES AND THE LIKE Filed Nov. 14, 1927 5 Sheets-Sheet 4 June 24, 1930. E. M. BYTHWAY LINK WORK FOR RECIPROCATING ENGINES AND THE LIKE.

Filed Nov. 14, 1927 5 Sheets-Shes; 5

Patented June 2 4, 1930 untrue STATES PATENT OFFICE EDWARD MELVILLE BYTI-IWAY, or SWANSEA, wALEs LINK-WORK non nncrrnocnrnve ENGINES AND THE LIKE,

Application filed November 14,1927, Serial No. 233,274, and in Great Britain November 19, 1926.

This invention has reference to link-work for coupling the piston rods of reciprocating engines and the like to their cranks, wherein pivoted and cranked levers are interposed for the purposeof more efliciently applyingthe power as shaft.

According to the present invention, a compensating and balancing link-work or w mechanism is provided whereby a substantially constant crank-leverage with no dead centering is obtained, the full piston power being distributed :evenly for useful work throughout theentire crank travel. Consequently a greater power output is obtainable from the crank-shaft than with reciprocating mechanism as hitherto provided.

In attaining the objects set out in the preceding paragraph, there is employed between piston and crankwhat may be termed virtually a compound lever of substantially arrow-head formation, the leg or stem of which is common to both arrow-head sides and the three arms acting simultaneously and in unison. The piston rod is coupled to. the leg aforesaid, and the other two arms or arrow-head sides are coupled, in any suitable manner and disposition, to apair of opposed crank-pins of the crank-shaft. It will 'be'seen later that the gear may be multiplied by the addition of other crank-pins on the crank-shaft driven by extra connecting rods and levers in a similar manner, and all actuated by the piston rod of 'one and the same piston, the plurality of the crank-pins being set to give the best results. said arrow-head lever may be set at any requisite angles to the stem which angles maybe equal or unequal.

The lever aforesaid may be acne-piece lever, or may be constituted by separate leg and other arrow-head arms fixedly connected to a rocker shaft, or it may be constituted by a one-piece member somewhat of an equilateral triangular shape. same as a triangular member, the same is fulcrumed centrally in its base at a point spaced from the longitudinal central'line of the piston rod, and at its apex coupled to 50 the outer end of said piston rod in such a The sides or arms of the Regarding position that when the piston'i's inits halfstroke position, a line connecting fulcrum and apex is perpendicular to said piston rod; the base at eachside of the said ful crum is connected by a connecting rod toa crank-pin of a two-throw crank-shaft. The length of the base arms is equal to half the length between fulcrum and apex.

Further, the main levers or stems may each be constituted by two side parallel pieces spaced-apart by rods and tie pieces for the carrying of the connecting rods to line up to various additional cranks, thus enabling a number of additional shafts being coupled up in series of cylinders for 4, 6 or S-throw crank-shafts.

Further, the invention readily lends itself for application to double acting cylindersof all types of internal combustion engines.

In order that the said invention may be the more readily understood, reference is to be had to the following description and accompanying sheets of drawings, wherein Figure 1 is a diagram showing the invention as applied to a two-throw crank-shaft and also to an additional two-throw crankshaft, a single horizontal cylinder being employed.

Figure 2 is a diagrammatic view showing the invention as applied to a four-throw crank-shaft, a single horizontal cylinder being employed.

Figure 3 is a diagram showing the invention as applied fordriving two'independent' two-throw crank shafts, a single horizontal cylinder being employed Figure l is a front view of a preferred arrangement of link-work embodied in Figure 1. I

Figure 5 is a side view of said link-work.

Figure 6 is a sectional plan view'taken on line L -00 of said Figure 5.

' Figure 7 is a side elevation, partly in section of the link-work'embo'died in Figure '2.

Figure 8 is a vertical sectional View on line y, 3 Figure 7 of said link-work.

Figure 9'isa View on line 3-3 of Fig" ure 7'illustrating the slide-block-reversing. mechanism at full stroke. V I I In carrying out the invention, the arrowhead fulcrum lever 1, 2, 2 shown in Figure 1 is in Figures 4, 5 and 6 incorporated in a single member of a substantially triangular or kite formation, the sides 4, 4 thereof cor responding to the lever arms 2, 2 of Figure l and the vertical web portion 3 corresponding to the leg 1 of Figure 1 said sides 4, 4 being offset from the web. portion 3 as shown. The kite-shaped member 3, 4, 4 is fixedly secured to the the fulcrum or rocker shaft 6 mounted in the framework 7 of the apparatus, said rocker shaft 6 being positioned above the longitudinal centre line of the piston rod 8 of the horizontally disposed cylinder 9 a distance equal to twice the length of an arm 2,.Figure 1.

The piston rod 8 at its outer end'is provided with a slide block 10 which carries a horizontally disposed pin 11 over which engages the slot 12 of the lower or tail end 13 of the central portion 3 of the kite member 3, 4, 4, the arrangement being such that, at half stroke of piston rod 8, said central portion 3 stands perpendicular to the piston rod 8 aforesaid.

To the outer end of each fulcrum arm or secondary lever 2, i. e. the upper and outer end of part 4 ofthe kite member 3, 4, 4, there is a socket 5 in which is pivotally connected the upper end of a connecting rod 14, which rods 14 by their lower or big ends are connected to the crank-pins of a mo throw crank-shaft15, so that as the piston rod 8 reciprocates the kite member 3, 4, 4, is rocked to and fro imparting, through its connecting rods 14, 14 a rotary ll'lOVGDlOllt to the crank-shaft 15 aforesaid.

Further, by the addition, as shown in Figure 1, of other arms 2 and additional connecting rods 16 coupled the one to the lever 1, and the other to said secondary levers 2, and both to the crank-pins of a supplemental crankshaft 17, rotary movement can be imported to said crank-shaft 17 simultaneously with the rotary movement of the crank-shaft 15 aforesaid.

Referring now to Figures 2, 7, 8 and 9 of the drawings, illustrative of the invention as applied to a four-throw crank-shaft.

In carrying out this arrangement, the linkwork is duplicated, that is to say, it com prises upper and lower rocker or fulcrum shafts 6, spaced equidistant from the piston rod 8, and suitably mounted in the upperand lower parts of the frame 7, each rocker shaft 6 being fitted with an arrow-head fulcrum lever, constituted by a main or fulcrum lever 1 and two-spaced-apart rocker bars 2, 2 fixedly secured to their rocker,

shaft 6, the one crank lever depending from its shaft 6, the other upstanding from its shaft 6, the main or fulcrum levers 1, 1 being, when the piston rod 8 is at halfstroke, in a right line and perpendicular to the piston rod 8 aforesaid.

The inner end of each main or fulcrum lever 1 is formed with a longitudinal slot 12, and each slot 12 engages over a pin 18 which extends horizontally and perpendicularly from a block 19 slidably mounted on a slide bar 20, said bars 20, which are arranged horizontally and side by side, being at their ends, suitably supported in brackets carried by the frame 7 of the apparatus.

In each end bracket there is rotatably mounted a sprocket wheel 21, and said sprocket Wheels 21 are coupled together by means of an endless chain 22 to the upper and lower parts of which the slide blocks 19 aforesaid are, respectively, fixedly secured, and with the pin 18 of the outer slide block 19 there engages the slide block 10 of the piston rod 8 of the horizontally disposed cylinder 9.

Further, the crank-pins of the four-throw crank-shaft 15, which in this case is positioned centrally between the upper and lower rocker shafts 6, are each connected by a connecting rod 14 to a rocker arm 2, the upper connecting rods 14 crossing one another, as also do the lower connecting rods.

The above arrangement is such that, piston rod 8 being at half-stroke, the main levers 1, 1 stand vertically and perpendicularly to said piston rod 8, whilst the slide blocks 19 aforesaid are in central alignment with one another. 1 On the piston rod 8 reciprocating, it carries with it the outer slide block 10 and outer main lever with the result that the inner slide block 19 is through the travel of the chain 22, travelled in reverse directions with consequent opposite movement of the inner main lever 1, that is to say, the cranklevers swing and cross one another in opposite directions and through the connecting rods 14 impart a constant even rotary motion to the crank-shaft 15 aforesaid.

It is to be understood, however, that this chain method of reversing the movement of a pair of main levers 1 (both operating on to a 4-throw crank shaft) is only an example of innumerable gears which may be used for the same purpose.

Further, the opposite of either pair of connecting rods 14 can, when required, be removed to allow of the link-work driving only two of the throws of the four-throw crank shaft 15, thus actually represented at 180 such crank-shaft 15 may be divided and detachably connect-ed together at 23, by any convenient means, to allow of the two working cranks Whenever necessary, being set to any desired variable angle but maintained in true relation to one another, the respective inoperative secondary arm levers being retained as balances.

' Alternatively, to the duplication of linkwork, both sets of link-work are arranged to one and the same side of the piston rod,

and for this purpose, the second main lever and its rocker arms are carried by a sleeve which is rockable on the upper fulcrum shaft, the rocker arms of thefirst main lever extending through suitable slots in the rocker sleeve aforesaid, the depending main lever of said sleeve being coupled to its corresponding slide block. 1

Referring now to Figure 3 of the drawings there is shown how two separate and independent two-throw crank-shafts 15 can be simultaneously driven, and, to find the necessary angle for the arms 2 of the main lever 1, it is only required to set a set square at centre of fulcrum 6 so as to cut the arc of circle 24 and the centre of any fixed point required for crankshaft, to provide for the necessary angle for the arms 2, both crankshafts 15 being, through the main lever 1, the arms 2 and connecting rods 141-, driven from a horizontal cylinder common to both.

Regarding dimensions for the link-work these are obtained by using the piston stroke as a basis. The important dimension to obtain (proportionate to this basis) is the length ofthe main lever 1 and it isfound that this should vary with possible exceptions in a direct ratio with the stroke. For the higher range of strokes a greater increase should be assigned to the lever length to give best results. i

In explanation, for strokes of 1 and 2" there has been fixed by experiment an optimum lever length of 25 in each case, there being no direct ratio increase in this case. Thereafter, for a stroke of 3" the lever length should be 25 increasing per 1 stroke. But after 12" stroke, it is better to increase the lever length 1 per 1 of increased stroke up to 24L stroke, after which the per 1" proportion is reverted to.

'In all cases the length of the side arms 2, 2 is maintained at one-half of the main lever length, as herein mentioned.

The throw of the crank or cranks on the crankshaft 15 should (in most cases) be equal to one-quarter of thepiston stroke, although a minimmn of 1 should be fixed; but it is pointed out that proportions other than the foregoing are embraced by the invention.

I claim I 1. Mechanism for translating reciprocating motion to rotary motion comprising a reciprocal power member, a rotary shaft, disposed at a predetermined angle with respect to one another, a pair of equal length crank arms on said shaft, a pivoted lever connected with said power member for oscillation by the latter, a pair of equal length arms rigid with said lever and disposed with respect to one another at the same angle as said crank arms, and links connecting said lever arms with said crank arms, respectively.

2. Mechanism for translating reciprocating motion to rotary motion comprising a reciprocal power member, a rotary shaft, two pairs of equal length crank arms on said shaft, a block connected with said power member for'reciprocation by the latter, means guiding said. block for movement in the same direction assaid power member, a pair of sprocket wheels, an endless chain trained over said sprocket wheels, said block being connected to one reach of said chain, a second block connected to the other reach of said chain, means guiding said second block for movement in the same direction as said power member and said first block, two pivoted levers connected, respectively, with said blocks for oscillation by the latter during reciprocation of said power member, a pair of equal length arms rigid with each lever, and links connecting said lever arms with related crank arms. 7

3. Mechanism for translating reciprocating motion to rotary motion comprising a reciprocal power member, a rotary shaft, a pair of equal length crank arms on. said shaft, a pair of sprocket wheels, an endless chain trained over said. sprocket wheels, a connection between said power member and said chain whereby reciprocation of the former reciprocates the latter, a block secured to said chain, a pivoted lever connected with said block for oscillation by the latter, a pair of'oqual length arms rigid with said lever, and links connecting said lever arms with said crank arms, respectively.

In testimony whereof I have affixed my signzature hereto this 3rd day of November, 192

EDVVABD MELVILLE BYTH /VAY. 

